Godot Architecture?

[ciarandg]

I'm trying to figure out some way to integrate Faust with Godot for game development. Godot supports C++ modules (using GDNative), so I figure there must be some way to pass signal values from a Faust program into an AudioStreamGenerator, but I can't figure out how to package it properly to do so. Any help would be greatly appreciated.

[sletz]

Can you provides some links on the AudioStreamGenerator stuff?

[ciarandg]

Sure, basically an AudioStreamPlayer node containing an AudioStreamGenerator can pass signal values to the audio engine using push_frame(Vector2). Here's a very simple demo project that implements a 440Hz sin oscillator: https://github.com/godotengine/godot-demo-projects/tree/master/audio/generator

Here's the main audio page in the docs (mostly deals with .wav and .ogg files, I haven't found it particularly useful): https://docs.godotengine.org/en/stable/tutorials/audio/index.html

AudioStreamPlayer and AudioStreamGenerator have their own pages in the API docs: https://docs.godotengine.org/en/stable/classes/class_audiostreamplayer.html https://docs.godotengine.org/en/stable/classes/class_audiostreamgenerator.html

Here's a basic sprite tween demo (sinusoidal) that fetches tween values from a C++ module: https://github.com/GodotNativeTools/GDNative-demos/tree/master/cpp/SimpleDemo

Hopefully that helps!

Edit: note that the 2D vector in push_frame(Vector2) contains the values for a stereo signal

[sletz]

It seems the last way (using a C++ module) is the only reasonable way. But in this simple example it is not clear how a audio processing node could be developed. Any more info on that?

[ciarandg]

Looks like I gave you the wrong demo for C++ submodules, here's the tweening one I meant to send (made by following this tutorial https://docs.godotengine.org/en/stable/tutorials/plugins/gdnative/gdnative-cpp-example.html) https://github.com/ciarandeg/gdnative-demo. Sorry about that.

As for making an audio processing node, I think the way you'd have to do it is to attach a .gdns script to an AudioStreamPlayer node and have that script pass the Faust patch's output values to its push_frame(vec2) function. In the tween example, gdexample.cpp directly calls the sprite's set_position(Vector2) function, so I figure it should be possible. Maybe that's clunky, though

[ciarandg]

Just spent some time playing around with audio stuff natively in Godot and I should have realized that GDScript is way too slow to be worthwhile for this in the first place. Going to just try writing my DSP code in C# so I can run it asynchronously instead. Closing the thread, thanks for the help

[sletz]

If C# is fast enough, then adding a new C# backend in the compiler could be a solution. But this is obviously a much more ambitious project. But anyway I'm interested to know if your "DSP code in C#" is a viable solution.

[ciarandg]

Thanks, and thank you for helping! I'm in way over my head honestly but fingers crossed